Function sparse_kronecker 

pub fn sparse_kronecker<F>(
    a: &CsrMatrix<F>,
    b: &CsrMatrix<F>,
) -> SparseResult<CsrMatrix<F>>
where
    F: Float + NumAssign + Sum + SparseElement + Debug + 'static,

Compute the Kronecker product C = A kron B.

If A is (m x n) and B is (p x q), then C is (mp x nq).